The objective of the proposed study is to relate the observed cell- cell adhesion of cultured skin fibroblasts from patients with cystic fibrosis in the presence of calcium ions with several possible biochemical changes in the plasma membrane. In this study, several membrane components which have been shown to be involved in the cell- cell adhesion will be examined. The content and distribution of these membrane components, including L-fucose, D-glucosamine, neuraminic acid, di- and tri-phosphotidylinositide, will be determined by using radioactive labeling techniques, SDS-polyacrylamide gel electrophoresis and carbohydrate staining methods. The activity of cell-surface galactosyltransferase will be determined by using N-acetylglucosamine as the galactosyl acceptor. In addition, the binding of calcium ions to plasma membranes will be measured in order to determine the relationship between the calcium binding and the adhesiveness of fibroblasts from patients with cystic fibrosis. Knowledge of the nature of the possible alteration(s) in plasma membranes of cells from patients with cystic fibrosis could provide insight into the pathogenesis as well as provide an accurate method for the prenatal detection and heterozygote identification.